Etching machine



Jan. 5, 1932. J. M. TOWNSEND ETCHING MACHINE 2 Sheets-Sheet Filed June 1, 1929 JIZW (Ere W9 5775101701921? 12 may? Jan. 5, 1932. J. M. TOWNSEND 1,839,511

ETCHING MAGHI NE Filed June 1, 1929 2 Sheets-Sheet 2 75% f WvM Patented Jan. 5, 1932 T" OF CE JOSEPH M TOWNSEND, OEWORCESTER, MASSACHUSETTS moraine Application filed June 1,

This invention relates to a machine for etching printing plates in abath of acid or the like. I

The principal objects of the invention are to provide a means for periodically and regu-' larly lifting the printing plate out .offthe bath and plunging it back into it repeatedly; to provide means for supporting the plate in a horizontal position so that it may be inw troduced into the bath uniformly over its entire area; to provide means ofv a simple and convenient character for tipping the plate up out of the bath to be inspected by the'operator and to provide for the protection of the machinery from the acid andother fumes of the bath.

Other objects and advantages of the i11- yention will appear hereinafter.

Reference isto be had'to the accompanying drawings in which Fig.1 is a perspective view showing-one embodiment of this inventiomand Fig. 2 is a similar view of another form. The usual method of applying the acid bath to plates for etching purposesis to spray or splash the liquid over the plate. It is necessary to apply the liquid and then allow the air to get to the plate a plurality of times during the etching operation and one object 7 of this invention is to arrang'eforthis action in a uniformand periodicfmanner so as to avoid irregular treatment of the plate.

The inventionis shownin Fig. 1 as embodied in a machine comprising a base 10 and two uprights 11. Each upright has a horizontal shelf 12, preferably integral withthc upright, and 011 these shelves rests the tank 13 containing the acid to be used.

he plate P is supported from a shaft 14 arranged horizontally. For this purpose the shaft is provided with two supports 15 clamped to the shaft. They are shown as slit longitudinally and provided with a bore for the shaft and a screw 16 for fixing them firmly to it. If desired, a fixed support 17 may be employed secured in the same way on a horizontal rod 18 which in turn is fixed by a clamp 19 to theshaft 14 in a similar way. These supports are provided with notches 20 in the bottom providing a'horizontal projecthe acid.

MACHINE 1929. Serial No. 367,741.

tion on which the plate rests and they are adjusted before being clamped soas to apply 'a slight pressure to the edge offthei p'late where it engages the slanting side of the notch. a i y This shaft 14 is supported in opentopped U -shaped yokes2l which are mounted] on the top of two vertical rods 22." These rods slide in bearings 23 on the uprights 11. At the bottom the rods 22 are provided withyokes 2 1 on which are rollers 25. Th'ese'rollers rest on and are operated by cains 26 and the yokes straddle 'a shaft 29. These cams are operated by a motor 27, gearing'28 and p i the shaft 29 onwhich they are located." f The shaft ltis heldup against theyokes 21 by collars 30 and onjthe end ithasfa'handle 31 by which the shaft canbeturned'. On one of the rods 22 is'asegment 32having two depressions 33f The handle 3lYha s ja knob '34 with aspring"plunger which sets into these depressions and holds the handle ineither one of the two positions; The shaft 14 therefore can be turned to bring the plate P up into substantially vertical position Wherethegoperatorflat the front can inspect the plate'and'then it can bev turned back 'to the position shown for operation. The operation is'v'e'ry simple. The'motor being started in any ordinary Way the .shalft 80. 29 will rotate regularly and the rods: 22 and the shaftl l will be raised and lowered peri- V odically." The motion is quitefsmallgjust enough to'raise theplate out of the liquid andplun'ge the lower face of it backintoit." It is not'intended to submerge 't heplate in In the form shown nism is .very, similarto that shown infig e 1 w but a metallic casing 39 is, provided for receiving the motor 27, shaft 29 andother *1118- chanical features of the operating means. This casing is used toprotect themifromfthe corrosion due to the acid fumes and1the like t which come from the bath of the etching liquid. In t-his case therefore the-motor 'and shaft operate'ftwo uprights 42 which are'not located near-the tank and' th'eseuprights carry horizontal arms 43 which canbead- QW the other drawings .7

The tank 13 is supported on a base at the proper height with respect to the arms 43-. This arrangement is provided to protect the machinery from the fumes" as stated. Otherwiseit operatesthe same as the construction fsflijojvn in F1'g .f1'. y Y

"By this means it will be seen that the treat irhentfo f theunder side of the plate by the acid is periodically regular and that the acid is allowed to act on the plate thepsame j'le'n gth of time at each submersion. The bot- :tom oftheplate also stays out in the air equal lperiods each time. The plate is subjected T to the acid allover its lower surface every it goes down and there is no danger zoff anyflpart of tha't" surface being missed even Tonf'ce during the full-treatment of the plate.

I'Iflie pl'at'e'i s lowered intothe acid slowly as "the 'shaft29 is rotated only once or twice per second. The number ofoperations will be ,dependentupon the'character of the work but wirerenumber of'plates that are all alike incharacte are being treated they can {allT-beintroduced into the acid the same num- Memes, so were get absolutely uniform J'tr" talent, notonly of each plate, but ofjany l-desi'red number of'plates'.

"Although I: have illustrated and described of a pair of reciprocating rods guided by J 1 7. 7 ,only one form of the invention 1 am aware f the fact that modifications can .be made T'therein by any person skilled in out departing from the' scope of the invention ,as expressed i'n'jthe claims. Therefore, I dokriot -wish tofb'e limited in this respect but do claim is:. I I

1. 111.311 etchng machine, the combination with a pair of uprights having projec- Ztionson their: inner sides and a tank for etching liquid supported on said projections,

uprights; means for reciprocatn'ig said rods, a shaft supported by said rods above "the and supports secured to the shaft the art witheach rotation of the shaft for the purpose of plunging the lower face of the plate into the liquid in the tank and withdrawing it therefrom.

3. In an etching machine, the combination of a tank for etching liquid, with a pair of rods, means for vertically reciprocating said rode, a shaft, meansconnected to move said rods for supporting said shaft above the tank, means clamped to said shaft for holding the platein the tank and means on said shaft for turning it to move the plate forwardly about the shaft as an axis for the purpose of inspection.

'4'. In an etching machine, the combination .of a tank for etching liquid, with a pair of rods, means for vertically reciprocating said rods, a shaft freely supported by said rods above the tank, means clamped to said shaft v for holding the plate at a distance'below the shaftin the tank, a segment on one of said rods havingdepressions at the ends, a handle on said shaft for turning it and a knob on the handle having a plunger adapted to enter either of said depressions and hold forward position with the surface to be etched in. front. c

5.1In an etching machine, the combination with a tank for-the etching liquid, of means for supporting a plate to be etched, means for raising the plate and submerging its lower surface in the liquid, and a casing surrounding the raising mechanism to protect it from the fumes of the etching bat-h.

6, In an etching machine, the combination with a tank for the etchingliquid, of means for supporting the plate to be etched in horizontal position and means for lowering the plate in the liquid and raising it out of the liquid a plurality of times during the etching operation, without changing the position of the surface to be etched from a position parallel with the; surface of the liquid, said means comprising reciprocable' rods having arms projecting-therefrom provided with open toppedbearings, a shaft carried by said bearings means depending from the shaft for supporting, in the tank the plate to be etched. a

In testimony whereof I have hereunto affixed my signature. V

JOSEPH M. TOWVNSEND.

ref hoieiag'a'prafiew be etched in theta-11k. i

In-an etching machine, the combination tank for etching liquid, of means for s'rrpportin-gsaid tank, a pair ofrods, a horiiziontal'fsha'fticarried by said rods. above the tank, a-series of supports. clamped to: the

ushafft, having means at their lower ends for j sirpporting and holding the pla-tes to be was vetched down in the tank a shaft below the I tank and camson-jsaid shaft adapted to raise and lower the rods andplate during the plate in a horizontal position or in a 

